Wireless communication systems have become ubiquitous in society. Business and consumers use a wide variety of fixed and mobile wireless terminals, including cell phones, pagers, Personal Communication Services (PCS) systems, and fixed wireless access devices (i.e., vending machine with cellular capability). Wireless service providers continually try to create new markets for wireless devices and expand existing markets by making wireless devices and services cheaper and more reliable. The price of wireless devices has decreased to the point where these devices are affordable to nearly everyone and the price of a wireless device is only a small part of the total cost to the user (i.e., subscriber). To continue to attract new customers, wireless service providers are implementing new services, especially digital data services that, for example, enable a user to browse the Internet and to send and receive e-mail.
Subscribers have shown great interest in using high-speed applications between mobile stations in wireless networks. Many of these high-speed applications (e.g., video phones) require a radio access network (RAN) that supports streaming data applications. A streaming data application must be transported over constant bandwidth with low delay and low levels of jitter. However, current wireless networks, such as cdma2000 RANs, often experience problems when supporting streaming data applications. Packet data transmissions between a base station (BS) and a mobile station (MS) experience delay and jitter at numerous points in the network, including at the air interface between the MS and the BS and at the interface between the BS and the packet data serving node (PDSN).
Delays and jitter would be minimized if streaming data could be transmitted more directly between mobile stations, without passing through some infrastructure of the radio access network (RAN), such as the PDSN. However, the well-known RAN signaling messages specified in TIA-2001-C, “Interoperability Specification for cdma2000 Access Network Interfaces”, Jun. 2003, (hereafter, simply “the TIA-2001-C standard”) and other standards do not provide for direct mobile-to-mobile (MS-MS) packet data calls. The TIA-2001-C standard only allows for mobile originated packet data calls.
All packet data calls use control signals that connect the base station (BS) serving the mobile station (MS) that originates a packet data call to a packet data serving node (PDSN). All data transmitted by a source mobile station is transferred through the PDSN to a packet data network. In the case of MS-MS packet data calls, the data is then transferred back to a base station of the wireless network for subsequent transmission to a destination MS. Obviously, transferring the data up to, and then back from, the PDSN is unnecessary and introduces delays. Additionally, the added signaling needed to establish connections to the PDSN increases call set up time and decreases success rates.
U.S. patent application No. 20,020,077,096 (hereafter, the “Jin application”) discloses a method for providing mobile station-to-mobile station data calls, provided the same base station (BS) serves both mobile stations. The method disclosed in the Jin application establishes MS-MS packet data calls without requiring connections between the BS and the PDSN. However, as noted, the mobile stations must be located in cells served by a single base station. This may be acceptable in a small wireless network that uses a single base station (e.g., a home or small office network). However, if a wireless network operator deploys a RAN with many base stations, this is a severe limitation. Subscribers who are distant from each other are served by different base stations and cannot engage in a MS-to-MS streaming data application without going through the PDSN and a wide area packet data network.
Therefore, there is a need for improved wireless networks that provide mobile station-to-mobile station (MS-MS) packet data connections that have low delay and low jitter characteristics. In particular, there is a need for a wireless network that provides a MS-MS packet data connection from a first base station to a second base station that does not require a packet data serving node and a wide-area packet data network. More particularly, there is a need for a wireless network that enables an MS-MS packet data connection handled by a first base station and a second base station to be transferred from the first base station to a third base station if one of the mobile stations is handed off from the first base station to the third base station.